In order to reduce losses during power transmission in the case of cable conductors with large cross sections of, for example, more than 100 mm2—and in particular more than 1000 mm2—in medium and high voltage cables, conductor designs formed from individual wires are increasingly used. Insulating materials are inserted between the individual wires or between segments constructed from individual wires. Alternatively, the individual wires are coated with insulating materials. Such conductor constructions minimize the undesirable skin and proximity effects, in particular in the case of large cross sections, so as to increase the transmission capacity of the cable or work with smaller cross sections.
The conductors are preferably divided into several segments, which are put together using tapes or other insulating layers to form conductors with a circular cross section. Inside the segments, the individual wires, which may also be insulated from one another, are twisted and drawn through a form mold, so that the current is subsequently conducted in the individual wires always following the wire course in the longitudinal direction of the cable from the external layer into the inside of the conductor. The segments are usually bound on the outside with tapes during production and are electrically insulated from one another. Such cable conductor constructions are known, for example, from U.S. Pat. No. 1,904,162 and are also referred to as a MILLIKEN design.
The economic advantage of this construction in terms of optimization of material costs has to be weighed against the disadvantage that the conductor preparation during installation requires significant effort and time to ensure that even the inner-lying wires of the conductor can make contact with the connecting point, and can then contribute to the power transmission. The insulating materials usually have to be completely removed from the conductor assembly. The individual wires must be freed from the insulating materials, unbent and brushed. Then, the individual wires are again brought together manually with the aid of hose clamps and pressing tools to form an almost circular shape with the diameter of the original conductor so that they can be introduced into the connecting element and adequately compressed and retained by it. The effectiveness of these measures is dependent on the care taken during assembly.
An apparatus with the features of the preamble of Claim 1 is known from EP 2 226 899 A1, in which apparatus a wedge-shaped lug acting as a contact medium can be radially screwed into a tubular clamping body, and can thus be brought into contact-making contact with the front ends of the two conductors that are axially inserted into the clamping body at opposite sides then electrical connection is established between the two conductors.